ADDIS ABABA  - South Sudan accused former foe Sudan on Friday of holding 35,000 Southerners as “slaves,” stalling talks to resolve to furious oil dispute as tensions remain high between the two neighbours. “There is unfortunately a disagreement, because the government of Sudan refused the inclusion of the freedom of about 35,000 South Sudanese enslaved citizens,” South Sudan’s chief negotiator Pagan Amum told AFP. Amum said the abductees were taken hostage during Sudan’s bloody 1983-2005 north-south civil war which ended in a peace deal.